1. Lecture 9: Data Storage Devices Intro to IT COSC1078 Introduction to Information Technology Lecture 9 Data Storage Devices James Harland james.harland@rmit.edu.au

2. Lecture 9: VideoIntro to IT Introduction Who is this bloke?

3. Lecture 9: Data Storage DevicesIntro to IT Introduction

4. Lecture 9: VideoIntro to IT Overview Questions? WebLearn Test 1 Assignment 1 Binary Representation Questions?

5. Lecture 9: AudioIntro to IT Introduction to IT 1 Introduction 2 Images 3 Audio 4 Video WebLearnTest 1 5 Binary Representation Assignment 1 6 Data Storage 7 Machine Processing 8 Operating Systems WebLearn Test 1 9 Processes Assignment 2 10 Internet 11 Internet Security WebLearn Test 3 12 Future of ITAssignment 3, Peer and Self Assessment

6. Lecture 9: Video SE Fundamentals Questions? How did you spend 6-8 hours on this course last week? This week?

7. Lecture 9: VideoIntro to IT Assessment Process Submit all assignments via Blackboard in the Learning Hub Assignment 1due 11.59pm Sunday 1 st April Assignment 2due 11.59pm Sunday 6 th May Assignment 3 due 11.59pm Sunday 27 th May Late assignments attract a penalty of 10% per day late, up to a maximum of 50%

8. Lecture 9: VideoIntro to IT Assignment Assignment will be in three parts Overall task is to produce a video Groups of up to 3 Assessed by final video and group blog Part 1: images and audio (end of week 5) Part2: hardware (end of week 9) Part 3: reflection, research (end of week 12)

9. Lecture 9: VideoIntro to IT Assignment 1 Use GIMP (or a similar tool) to perform some manipulations on an image Use Audacity to perform some manipulations on sound Use a movie making tool to produce something like (and much better than!) Lord of the Controllers 1 & 2 Email me your group and its name so that I can set up a blog on the Learning Hub

10. Lecture 9: Data Storage DevicesIntro to IT Overview 01010100001010101010100110100010101001101001010010 100011100010101010100101111001001010…

11. Lecture 9: Data Storage DevicesIntro to IT What do computers do? Compute! Input/Output Processing Memory

12. Lecture 9: Data Storage DevicesIntro to IT History … Babbages Difference Engine (1849) Babbages Analytical Engine (1837-1871, never built) Turings Universal Machine (1936, mathematical model) Turing digital Boolean-logic multiplier (1937) Colossus (1943, destroyed 1945) ENIAC (1946) Von Neumann architecture (c. 1945) EDVAC (1949) CSIRAC (1949)

13. Lecture 9: Data Storage DevicesIntro to IT Overview Thomas the Tank Engine

14. Lecture 9: Data Storage DevicesIntro to IT Overview Video Audio Text Thumbnails

15. Lecture 9: Data Storage DevicesIntro to IT Memory via `Flip flops or and not 1 0 0 0 0 0 0 0 1

16. Lecture 9: Data Storage DevicesIntro to IT Memory via `Flip flops or and not 0 1 1 1 1 1 1 0

17. Lecture 9: Data Storage DevicesIntro to IT Memory via `Flip flops Can design other versions of flip-flops Shows how circuits can be designed using AND, OR, NOT (NAND, NOR, XOR, …) in combinations (gates) Hierarchy and abstraction Shows how electric circuits can store values

18. Lecture 9: Data Storage DevicesIntro to IT Computer Memory Cells of 8 bits each (one byte) Most significant bit Least significant bit … … address

19. Lecture 9: Data Storage DevicesIntro to IT Random Access Memory (RAM) Random access means any cell can be accessed at any time (and in any order) Volatile – contents cleared when machine is switched off Very fast compared to other forms of memory DRAM: dynamic RAM (replenishes charges constantly) SDRAM: synchronous DRAM – faster still Often have small very fast caches and registers

20. Lecture 9: Data Storage DevicesIntro to IT Magnetic Disk Thin spinning metal disk with magnetic coating Each disk contains a number of circular tracks Often several disks stacked on top of each other Cylinders made up of tracks made up of sectors Can have very large storage this way Slow access time!

21. Lecture 9: Data Storage DevicesIntro to IT Magnetic Disk (Hard Disk) Seek time: move heads from one track to another Latency time: half time for complete disk rotation Access time: seek time + latency time Transfer rate: rate data can be read from disk `Typical Hard disk Seek time: 2ms to 15ms Latency time: 8ms to 20ms Transfer rate: 0.5 GB per second Sounds fast, but is actually quite slow …

22. Lecture 9: Data Storage DevicesIntro to IT Optical Disks (CDs, DVDs) Laser readers rather than magnetic ones Disks more error-tolerant than magnetic ones TypeFeaturesDateStorage CDcompact disk1984800MB DVDMultiple layers199515GB Blu-ray`blue laser (405 vs 650 nm) 2004100GB

23. Lecture 9: Data Storage DevicesIntro to IT Flash Drives Disks of all sorts are slow compared to other circuits Flash drives write small electronic circuits Eventually decay after many changes of data Suitable for slow-changing data, not main memory Portable and much more resilient than disks

24. Lecture 9: Data Storage DevicesIntro to IT Older Storage Types Magnetic tape `Floppy disk (5.25 disk) 3.5 disk

25. Lecture 9: Data Storage DevicesIntro to IT Conclusion Get Assignment done this week Dont forget to blog … Keep reading! (book particularly)